1. Field of the invention
This invention relates to motion picture cameras for use with film having a sound track arranged in cartridges, and more particularly to improvments in arrangement of the sound recording means in the cartridge chamber defined in the camera housing and in construction of a mechanism which actuates and releases the sound recording means to and from their operative state respectively in response to an actuation and a release of the shutter release member. Still more particularly the invention relates to a motion picture camera provided with a manually switchable picture image frame frequency control device in combination with locking means therefor.
2. Description of the prior art
Over the years, there has been a wide acceptance in the use of easily manageable cartridges for motion picture film in miniature photography applications. Until comparatively lately, however, the motion picture arts have lacked compact cartridges for roll film with sound track which facilitate loading and sound-image synchronous recording operations. In recent years, the increasing requirement for film with sound track in many photography applications has led to development of cartridges capable of use in sound motion picture cameras, as for example, disclosed in U.S. Pats. Nos. 3,561,851 and 3,604,790.
In loading such cartridges in motion picture cameras in quick and steady fashion which is the most useful phase of the versatility of cartridge, the requirements for accuracy of the loaded position and state are such that the exposure window of the cartridge received in a chamber defined in the camera housing is accurately positioned in alignment with a lens system in the camera, and in addition the portion of the filmstrip positioned adjacent a cutout provided in a portion of the film channel of the cartridge be so correctly positioned with respect to the sound recording means that upon actuation of the latter for sound recording operation, the sound track provided on the vicinity of one edge of the filmstrip is brought into operative relationship with the sound recording elements such as a sound head and a pinch roller extending into the cutout of the cartridge. For this reason, commercially available motion picture cameras with sound recording means mounted therein in fashions known in the prior art cannot receive cartridges for film with sound track without the necessity of complicated time-consuming loading procedure.
In addition to the aforsaid problem, there is another problem that when taking a motion picture sequence with sound accompaniments, the film transporting mechanism should be set to the particular film transportion speed, namely, the particular picture image frame frequency suitable for the sound recording operation, or otherwise unacceptable sound effect will result. In the case of motion picture cameras regulatable to various frame frequencies, it is known to arrange a manually switchable frame frequency control device in the film transporting mechanism but independently of the sound recording means, said device having a plurality of switched positions including a position for recording sound accompaniments with the motion pictures on the filmstrip. With such an arrangement, it has been possible, should an incorrect setting be made, thereby the filmstrip advances across the sound recording station at a speed other than that suitable for sound recording operation.